Biotium Launches New Phalloidin Conjugates with Extended F-actin Staining Stability for Greater Imaging Flexibility

Long-lasting, bright F-actin staining made easy with Biotium’s new ActinBrite™ High Affinity Phalloidin Conjugates

May 9, 2025 – FREMONT, CA — Biotium, a leading developer of fluorescent reagents for life science research, is proud to introduce ActinBrite™ High Affinity Phalloidin Conjugates — a new generation of fluorescent phalloidin conjugates engineered to preserve exceptional binding affinity to F-actin for bright, reliable staining that lasts up to a month after staining.

Traditional phalloidin conjugates can have weakened affinity due to dye modification, leading to loss of signal over time after staining. In contrast, ActinBrite™ conjugates maintain strong F-actin interaction, allowing stained samples to retain fluorescence intensity and specificity for far longer. This advancement offers scientists greater flexibility for downstream imaging, particularly for academic experiments requiring extended storage, imaging at a later time, or large-scale batch staining.

Key Features of ActinBrite™ High Affinity Phalloidin Conjugates:
Strong Binding: Preserves high F-actin binding affinity for bright, stable staining
Stable Signal: Staining remains stable for over a month (depending on conjugate and mounting method)
Flexible Imaging: Enables delayed imaging without loss of signal or specificity up to 1 month
Color Options: Available in 5 colors from green to near-IR for flexible multiplexing
Compatible: Direct replacements for conventional phalloidin conjugates

PFA-fixed, Triton® X-100 permeabilized HeLa cells were stained with ActinBrite™ 488/505 High Affinity Phalloidin, ActinBrite™ 665/690 High Affinity Phalloidin, or the leading competitor dye phalloidins with spectrally similar excitation and emission. Cells were imaged in EverBrite™ Mounting Medium, then stored at 4°C, protected from light, and imaged again using the same microscope settings after 15 days.

ActinBrite™ conjugates are ideal for imaging F-actin in fixed cells and tissues across a range of applications, including cytoskeletal studies, cell morphology analysis, and multiplex fluorescence imaging. This product line adds to Biotium’s broad portfolio of superior cellular stains and fluorescent probes.

Learn more about ActinBrite™ High Affinity Phalloidin Conjugates. Biotium also offers other unique solutions for cytoskeletal staining, including ViaFluor® Live Cell Microtubule Stains, and a wide array of Phalloidin Conjugates, available in 17 bright and photostable CF® Dyes.

About
Biotium is a leading life science reagent manufacturer and supplier devoted to providing high-quality and innovative fluorescent tools that fuel scientific discovery. Our collaborative team of experienced chemists and biologists, who are at the forefront of fluorescent dye design, apply chemistry-based principles toward producing solutions for unmet challenges in life science and medical research. Since its founding in 2001, Biotium has developed over 30 patented technologies that have been licensed out to leading life science technology companies worldwide.